1. Field of the Invention
The present invention relates to an ultrasonic diagnostic apparatus, a diagnostic imaging apparatus, and a program for diagnosis by imaging internal organs of a patient. In particular, the present invention relates to an ultrasonic diagnostic apparatus, a diagnostic imaging apparatus, and a program, which form three-dimensional images of internal organs of a patient, and display the three-dimensional images by using ultrasonic waves.
2. Description of the Related Art
An ultrasonic diagnostic apparatus enables real-time observation of sectional images of a patient. In recent years, an ultrasonic diagnostic apparatus capable of acquiring and displaying three-dimensional image data at high speed has been rapidly developed. An ultrasonic diagnostic apparatus capable of acquiring and displaying three-dimensional sectional images and dynamic images consisting of three-dimensional sectional images has been provided.
For diagnosis of a heart and an area close to a heart, it is necessary to obtain real-time sectional images with sufficient time resolution, because a heart works fast. Therefore, an ultrasonic diagnostic apparatus is indispensable for diagnosis of a heart and an area close to a heart, and its importance has been increased in recent years.
However, an ultrasonic diagnostic apparatus has following problems. For example, comparing with large diagnostic imaging apparatus, such as a CT scanner and MRI apparatus, an observable range is narrow. For an ultrasonic diagnostic apparatus, it is difficult to observe a wide area including a concerned area, for example, a whole organ such as a heart.
Further, in a heart and an area close to a heart, there are obstacles hard to transmit ultrasonic waves. Therefore, when a heart is observed by an ultrasonic diagnostic apparatus, an echo window observable by using ultrasonic waves is limited by the lungs and ribs surrounding the heart, and it is very difficult to observe the whole heart from an echo window at one location.
Namely, an ultrasonic diagnostic apparatus is difficult to acquire and display sectional diagnostic images clearly showing a whole heart of a patient. Therefore, under the present circumstances, when inspecting a heart, an inspector selects a most suitable echo window from those of each part of a heart, or according to variations among individuals. Such ultrasonic inspection of a heart requires various inspection techniques, and much time is required to master the techniques. The ultrasonic inspection itself requires long time.
In recent years, even a large diagnostic imaging apparatus such as a CT scanner and a MRI apparatus can acquire and display three-dimensional diagnostic images of a heart in detail by using sectional diagnostic images acquired in synchronization with an electrocardiogram. Therefore, it is possible to diagnose a heart by comparing the sectional images of a heat obtained by an ultrasonic diagnostic apparatus and various modality apparatus such as a CT scanner and a MRI apparatus.
However, when three-dimensional images of a heart obtained by an ultrasonic diagnostic apparatus and a CT scanner, for example, a acquirable/displayable area is limited in a three-dimensional image obtained by an ultrasonic diagnostic apparatus, and it is difficult to find an image showing the same area as that in a three-dimensional image obtained by a CT scanner. Further, even when three-dimensional images obtained by an ultrasonic diagnostic apparatus are displayed side by side, each display area is limited, and it is difficult to compare the images.
In the above circumstances, the following technique has been proposed in Jpn. Pat. Appln. KOKAI Publication No. 2006-122657, for example. The Jpn. Pat. Appln. KOKAI Publication No. 2006-122657 discloses an ultrasonic diagnostic apparatus, which includes an array oscillator comprising oscillation elements arranged like a concaved cylinder, and a transmission/reception means connected to the array oscillator, wherein the oscillation elements consist of lines of oscillation elements aligned along the axis of the cylinder, each line of the oscillation elements consist of lines of oscillation elements aligned along the circumference of the cylinder, the transmission/reception means executes first electronic scanning along the axis of the cylinder, as electronic sector scanning or electronic linear scanning, and executes second electronic scanning along the circumference of the cylinder, as electronic linear scanning. The ultrasonic diagnostic apparatus disclosed in the Jpn. Pat. Appln. KOKAI Publication No. 2006-122657 can transmit and receive ultrasonic waves through a clearance in a structure in a living body.
However, according to the technique disclosed in the Jpn. Pat. Appln. KOKAI Publication No. 2006-122657, though a two-dimensional array probe improved to have a shape easy to insert into a clearance between ribs of a patient, the specialized shape makes it difficult to manufacture the probe itself. Further, the technique disclosed in the Jpn. Pat. Appln. KOKAI Publication No. 2006-122657 is not a technique to enable improvement of picture quality by an ultrasonic wave radiation angle or depth, and does not absolutely solve the above problem.